Use of sea urchin spines with chitosan gel for biodegradable film production.

In recent years, the film production from natural polymers has considerably increased in food industry as an alternative to the petroleum based synthetic films. Chitosan is one of the most preferred biopolymers for bio-based film production, due to its biocompatibility, biodegradability, antioxidant activity and antimicrobial properties. Because of its hydrophilic properties, chitosan based films dissolve in water, limiting its uses in industry, to overcome this problem; we mixed 200 and 400 mg of the sea urchin spine powder (SUSP) with 20 mL chitosan gel respectively, to obtain a hydrophobic film. The chitosan films prepared with 200 mg SUSP showed a rise in the degree of contact angle from 70.2° to 107° providing hydrophobicity properties. On the other hand, addition of 400 mg of SUSP to chitosan film resulted in a contact angle of 96.1°. Moreover, the antioxidant activity and thermal stability of the films were increased in the presence of SUSP. Fourier Transform Infrared Spectrophotometry results proved the interactions between chitosan and SUSP. Chitosan films have smooth surface while SUSP blended films have rough surface morphology. These results demonstrated that SUSP is needed to improve the properties of chitosan films for usage in food industry.